The 22-year-old stadium underwent $250 million in improvements in 2007 but is still falling behind the competition with new stadiums opening in Dallas, Phoenix, Indianapolis and New York, Goodell said Monday.

Miami will host the Super Bowl for an NFL-record 10th time Feb. 7. Goodell spoke at a kickoff luncheon for the game.

"They've done a great job hosting Super Bowls here in the past," Goodell said. "The key thing is to make sure the stadium is state of the art and that it can compete with the stadiums in some of these other communities. They are moving to another level in some of these stadiums."

Deficiencies with the Dolphins' home include lighting and the location of lower-level seats, which are not close to the playing field. The league doesn't seek a retractable roof, Goodell said.

Dolphins owner Stephen Ross said the franchise is studying possible upgrades. It's unclear whether the team and league will seek public money. Ross said the Dolphins have yet to come up with a cost estimate or a proposed source of funding.

"We're looking at different ideas," Ross said. "We're still in the planning stage, and it's premature to talk about dollars. We know it's hard to put up dollars in South Florida in this economy.

"We're trying to keep it as low as possible and work with the league. We've got to show a package. That's what we're looking to do - put together a package."

A new stadium isn't being considered, Ross said.

The Pro Bowl will be played in Miami for the first time Jan. 31. Goodell supported experimenting with a new location and schedule slot for the all-star game, which in recent years has been played in Hawaii the week after the Super Bowl.

"If this doesn't work out, it will be my fault," Goodell said.

On other subjects, the commissioner said:

-Players perform in a "very safe environment," thanks in part to recent stricter league guidelines regarding concussions. "We're all learning more about concussions, the medical community as well as the NFL. We've been studying this for 15 years and have changed our policies as the medical science becomes more advanced. Everyone is treating this more conservatively, as they should. It's a serious injury, and you have to be careful. You want to make sure it heals properly."

-Negotiations on a new labor agreement are progressing slowly, with another meeting scheduled this week. "The good news is we're talking. It's pretty clear that things don't happen until you get your back up against the wall a little bit. I would expect as we get a little closer to an uncapped season (in 2010) that things will be a little more focused."

-Despite the league's plan to cut a $100 million annual supplemental revenue-sharing program that subsidizes lower-revenue franchises, teams will still spend competitively. "We have great revenue sharing in the league. We have a number of systems we have collectively bargained that will ensure that."